5.1.4 Hormonal communication Flashcards
What is the the difference between endocrine and exocrine?
Exocrine - secretion of chemical outside of blood e.g. digestive enzymes
Endocrine - secretion of chemical inside of blood e.g. hormones
What hormones does the pituitary gland secrete? Give their functions
- Growth hormone: controls growth of bones and muscles
- ADH: increases reabsorption of water in kidneys
- Gonadotrophin’s: control development of ovaries and testes
What hormone does the adrenal gland secrete? Give it’s function
- Adrenaline: increases heart, breathing rate and raises blood sugar level
What hormone does the pineal gland secrete? Give it’s function
- Melatonin: affects reproductive development and daily cycles e.g. sleep cycle
What hormone does the thyroid gland secrete? Give it’s function
- Thyroxine: controls rate of metabolism
What hormone does the thymus secrete? Give it’s function
- Thymosin: promotes production and maturation of white blood cells
What hormones does the pancreas secrete? Give their functions
- Insulin: converts glucose to glycogen in the liver
- Glucagon: converts glycogen to glucose in the liver
What hormones does the ovaries secrete? Give their functions
- Oestrogen: controls ovulation and secondary sexual characteristics
- Progesterone: prepares the uterus lining for receiving an embryo
What hormone does the testes secrete? Give it’s function
- Testosterone: controls sperm production and secondary sexual characteristics
Why can steroid hormones pass through the cell membrane?
They are lipid soluble
How do steroid hormones work?
- Bind to steroid hormone receptors within cytoplasm or nucleus
- Hormone-receptor complex acts as a transcription factor which promotes or inhibits transcription of specific gene
- e.g. oestrogen
Why can non-steroid hormones not pass though cell membrane?
Hydrophilic so will be repelled by fatty acids
How to non-steroid hormones work?
- Bind to specific receptors on cells surface membrane
- Triggers cascade reaction mediated by secondary messengers
- e.g. adrenaline
Differences between hormonal and neuronal communication?
Hormonal
- Slower transmission and response
- Hormones travel to all parts of body
- Widespread response
- Long lasting response
- Effect permanent and irreversible
Neuronal
- Faster transmission and response
- Hormones travel to specific parts of body
- Localised response
- Short-lived response
- Effect temporary and reversible
What is the adrenal cortex?
- Outer region of the gland
- Produces hormones vital to life e.g. cortisol and aldosterone
- Steroid hormones
What is the adrenal medulla?
- Inner region of the gland
- Produces non-essential hormones e.g. adrenaline and noradrenaline
- Non-steroid hormones
What is the function of adrenaline?
- Increases heart rate
- Increases blood glucose concentration levels
What is the function of noradrenaline?
- Works with adrenaline in response to stress
- Increases heart rate
- Widens pupils
- Widens air passages in lungs
- Narrows blood vessels in non-essential organs
What is the function of aldosterone?
Controls blood pressure by maintaining balance between salt and water concentrations
What is the function of androgens?
Male and female sex hormones important in menopause
What is the function of cortisol?
Regulates carbohydrate metabolism, blood pressure and cardiovascular function
How is the pancreas an exocrine gland?
Produces digestive enzymes (trypsin, lipase and amylase) and pancreatic juice which are released via pancreatic duct
How is the pancreas an endocrine gland?
Produces hormones (insulin and glucagon) which are released into blood
Which cells in the Islets of Langerhans produce and secrete glucagon?
α cells
